Bottom Line:
But the interrelationship between tumor metabolism and chromatin architecture remain unclear.Using complementary methods including Micrococcal nuclease (MNase) digestion assay, electron microscope and immunofluorescence staining, we demonstrate that glycolysis inhibition by pharmacological and genetic approaches was associated with induction of compacted chromatin structure.This condensed chromatin status appeared to result chiefly from histone hypoacetylation as restoration of histone acetylation with an HDAC inhibitor reversed the compacted chromatin state.

Affiliation: Department of Genetics and Complex Diseases, Harvard School of Public Health, Boston, MA 02115, USA.

ABSTRACTMetabolic rewiring, specifically elevated glycolytic metabolism is a hallmark of cancer. Global chromatin structure regulates gene expression, DNA repair, and also affects cancer progression. But the interrelationship between tumor metabolism and chromatin architecture remain unclear. Here we show that increased glycolysis in cancer cells promotes an open chromatin configuration. Using complementary methods including Micrococcal nuclease (MNase) digestion assay, electron microscope and immunofluorescence staining, we demonstrate that glycolysis inhibition by pharmacological and genetic approaches was associated with induction of compacted chromatin structure. This condensed chromatin status appeared to result chiefly from histone hypoacetylation as restoration of histone acetylation with an HDAC inhibitor reversed the compacted chromatin state. Interestingly, glycolysis inhibition-induced chromatin condensation impeded DNA repair efficiency leading to increased sensitivity of cancer cells to DNA damage drugs, which may represent a novel molecular mechanism that can be exploited for cancer therapy.

Mentions:
Given that inhibition of glycolysis was associated with induction of histone de-acetylation as well as condensed chromatin configuration, we wondered whether glycolytic metabolism might affect chromatin organization via modulation of histone acetylation. Treatment with a HDAC inhibitor panobinostat (80 nM, 24 hour) blocked the decrease of histone acetylation in 2-DG-treated cells (Figure 4A), resulting in almost complete restoration of the level of histone acetylation. We went on testing the effect of this HDAC inhibitor on glycolysis inhibition-induced change in chromatin structure. TEM analysis of cell nuclei showed that the condensed nuclear structures in 2-DG-treated cells were substantially diminished by addition of the HDAC inhibitor (Figure 4B). Immunofluorescence staining further confirmed that glycolytic metabolism regulated chromatin organization via modulation of histone acetylation. As shown in Figure 4C, glycolysis inhibition-induced heterochromatin like structure such as DAPI-rich, HP1 and H3K9me3 staining was abrogated by the treatment with the HDAC inhibitor. The results together implicate that elevated glycolysis in cancer cells enhances histone acetylation leading to an open chromatin state.

Mentions:
Given that inhibition of glycolysis was associated with induction of histone de-acetylation as well as condensed chromatin configuration, we wondered whether glycolytic metabolism might affect chromatin organization via modulation of histone acetylation. Treatment with a HDAC inhibitor panobinostat (80 nM, 24 hour) blocked the decrease of histone acetylation in 2-DG-treated cells (Figure 4A), resulting in almost complete restoration of the level of histone acetylation. We went on testing the effect of this HDAC inhibitor on glycolysis inhibition-induced change in chromatin structure. TEM analysis of cell nuclei showed that the condensed nuclear structures in 2-DG-treated cells were substantially diminished by addition of the HDAC inhibitor (Figure 4B). Immunofluorescence staining further confirmed that glycolytic metabolism regulated chromatin organization via modulation of histone acetylation. As shown in Figure 4C, glycolysis inhibition-induced heterochromatin like structure such as DAPI-rich, HP1 and H3K9me3 staining was abrogated by the treatment with the HDAC inhibitor. The results together implicate that elevated glycolysis in cancer cells enhances histone acetylation leading to an open chromatin state.

Bottom Line:
But the interrelationship between tumor metabolism and chromatin architecture remain unclear.Using complementary methods including Micrococcal nuclease (MNase) digestion assay, electron microscope and immunofluorescence staining, we demonstrate that glycolysis inhibition by pharmacological and genetic approaches was associated with induction of compacted chromatin structure.This condensed chromatin status appeared to result chiefly from histone hypoacetylation as restoration of histone acetylation with an HDAC inhibitor reversed the compacted chromatin state.

Affiliation:
Department of Genetics and Complex Diseases, Harvard School of Public Health, Boston, MA 02115, USA.

ABSTRACTMetabolic rewiring, specifically elevated glycolytic metabolism is a hallmark of cancer. Global chromatin structure regulates gene expression, DNA repair, and also affects cancer progression. But the interrelationship between tumor metabolism and chromatin architecture remain unclear. Here we show that increased glycolysis in cancer cells promotes an open chromatin configuration. Using complementary methods including Micrococcal nuclease (MNase) digestion assay, electron microscope and immunofluorescence staining, we demonstrate that glycolysis inhibition by pharmacological and genetic approaches was associated with induction of compacted chromatin structure. This condensed chromatin status appeared to result chiefly from histone hypoacetylation as restoration of histone acetylation with an HDAC inhibitor reversed the compacted chromatin state. Interestingly, glycolysis inhibition-induced chromatin condensation impeded DNA repair efficiency leading to increased sensitivity of cancer cells to DNA damage drugs, which may represent a novel molecular mechanism that can be exploited for cancer therapy.